#include<cstdio>
#include<iostream>
#include<cstring>
#include<unistd.h>

int main(){
  //库函数
  printf("hello printf\n");
  fprintf(stdout,"hello fprintf\n");
  const char *s="hello fwrite\n";
  fwrite(s,strlen(s),1,stdout);
  //系统调用
  const char *ss="hello write\n";
  write(1,ss,strlen(ss));
  fork();
  //向标准输出打印stdout,cin>1
 // std::cout<<"hello cout"<<std::endl;
 // printf("hello printf\n");
  //向标准错误进行打印stderr,cerr->2
 // std::cerr<<"hello cerr"<<std::endl;
 // fprintf(stderr,"hello stderr\n");
  return 0;
}
